Textile material and method of making the same



Patented May 1, 1934 UNITED STATES TEXTILE MATERIAL AND METHOD OF MAKING THE SAME Camille Dreyfus, New York, N. Y., and George Schneider, Montclair, N. J.,

assignors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application May 21, 1930, Serial No. 454,512

2 Claims.

This invention relates to the preparation of staple fibres of artificial filaments or threads made of organic derivatives of cellulose which may be associated together by spinning successfully.

5 An object of our invention is to prepare comparatively short lengths or staples of filaments of organic derivatives of cellulose which may be successfully associated together to form spun yarn.

Other objects of our invention will appear from the following detailed description.

The formation of spun yarn from comparatively short lengths or staples of filaments or threads composed of organic derivatives of cellulose and which have been prepared in the ordinary manner presents serious difficulty. This is due to the fact that such filaments or threads have such physical characteristics that they do not adhere to each other or intertwine sufilciently to form commercially spun yarn.

We have found that if filaments or threads, made for example of cellulose acetate, are stretched after they have been formed, their physical characteristics are so changed, that when they are cut into relatively short lengths or staples, such staples may be successfully associated togather in a spinning operation to form a commercially useful spun yarn.

In accordance with our invention, we stretch 0 filaments, threads or yarns made of organic derivatives of cellulose after their formation and then out such filaments or threads into compara tively short lengths, staples or chapp which may then be subjected to a spinning operation whereby the same are associated together to form spun yarn.

The filaments, threads or yarns employed in our invention may be made of any suitable organic derivative of cellulose such as organic cs- 40 ters of cellulose and cellulose ethers. Examples of such organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate, while examples of cellulose ethers are ethyl cellulose, methyl cellulose and benzyl cellulose. While the greatest advantages accrue from the spinning of short lengths of such filaments or threads solely, they may be associated with fibres of other materials such as cotton, natural silk, wool or reconstituted cellulose and then spun.

The artificial filaments of organic derivatives of cellulose may be formed from solutions of the same in suitable solvents by extruding such solutions through orifices into a drying evaporative atmosphere as in dry spinning, or by extrusion through orifices into a bath containinga precipitating liquid as in wet spinning. Such filaments may be stretched and cut whilein the untwisted state by our process, or two or more of such filamerits may be associated together by twisting to form yarns or threads, which yarns or threads may be stretched and cut by our process.

The filaments or yarns are stretched after their formation so that their length is increased from 5 to 25% or more. This may be done by passing the filaments or yarn around two or more rollers which are rotating at progressively greater peripheral speed. These rollers may be of the same size and rotated at progressively higher speeds of rotation, or the rollers may be of progressively larger size which may be rotated at the same or greater speed. The filaments or yarns may be passed through the stretching rollers from suitable packages, but for economy we prefer to stretch them immediately after their formation in the spinning machine.

After stretching of the filaments or yarns, they are cut into staple lengths varying from 1" to 20 or more, preferably from 1.5 to 2". While the yarns or filaments after they are stretched so may be wound on packages and then drawn from such packages to the cutting machine, we prefer to pass them directly from the stretching rollers to the cutters. The artificial filaments may be of any suitable weight per unit length, say from 5 1 to 30 denier or more, examples of which are 1.9,

3.5 or 5.5 denier.

The short lengths of filaments or threads are then subjected to a suitable spinning operation such as is used for the spinning of short lengths of natural silk, cotton or wool fibres to form threads by any of the well-known systems such as the cotton, the French, the worsted, the wool, the spun silk, the Bradford system or any other system. This spinning operation also 5 includes the preliminary treatments necessary to present the filaments or fibres in the form required for the actual operation of twisting them into yarn.

As specific examples of modes of carrying out 10 our invention the following are given.

3 ends of yarn of 150 denier each containing 40 filaments of acetone-soluble cellulose acetate in the untwisted state are drawn directly from the spinning machine in which they are formed and passed over a wick supplying water to the yarn on to a first roller rotating at 234 R. P. M. The yarn is wrapped around the roller twice, each wrap passing through a stationary guide and then is passed on to and wrapped twice in the same manner around a second roller of the same size which is rotating at 2'76 R. P. M. The yarn is thus stretched so that its length increases approximately 1'7.9%. The yarn so stretched is passed directly to a cutting machine to cut the same into staple fibres of 1.5" length. This staple rotating at 234 R. P. M. and are wrapped around this roller 6 times, the yarns being passed through a fixed guide between each wrap. Two wraps may be passed through each guide, thus requiring three guides for the first roller. Afterleaving the first roller, the ends of yarn are passed to a second roller rotating at 276 R. P. M. upon which they are wrapped '7 times, the yarn being passed through a fixed guide between each wrap, two wraps through each of three guides and one wrap through a fourth guide. The yarn is thus stretched so that its length increased approximately 13%. The yarn so stretched is passed directly to a cutting machine wherein it is cut into staple fibres of 1.5 length and these staple fibres may be spun in any desired manner.

By the stretching of the yarns or filaments before they are cut in accordance with our invention, staple fibres are formed which may be successfully spun on a commercial scale. This is a marked improvement over the use of staple fibres from unstretched filaments since these entail a great waste in spinning operations.

It is to be understood that the foregoing description is given merely by way of. illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. In the method of forming spun yarn containing organic derivatives of cellulose, the steps of extruding a solution of an organic derivative of cellulose through orifices into a setting medium to form filaments and stretching said filaments concomitantly with their manufacture by passing them directly from the spinning machine around a roller rotating at a predetermined peripheral speed and then around a second roller rotating at a greater peripheral speed and cutting said filaments immediately after the stretching operation.

2. In the method of forming spun yarn containing cellulose acetate, the steps of extruding a solution of cellulose acetate through orifices into a setting medium to form filaments and stretching said filaments concomitantly with their manufacture by passing them directly from the spinning machine around a roller rotating at a predetermined peripheral speed and then around a second roller rotating at a greater peripheral speed and cutting said filaments immediately after the stretching operation.

CAMILLE DREYFUS. GEORGE SCHNEIDER. 

